Along an assembly line, after painting of the vehicle body and doors has occurred, typically, each door is removed from the vehicle body after pulling out the hinge pin, so that the usual components can be assembled therein, namely, window glass, the drive mechanism therefor, door lock, outside mirror, and appropriate handles.
Heretofore, difficulties have been encountered in reassembling the completed door on the pillar of the vehicle. Hinge assembly brackets on the respective door and pillar are placed together and aligned so that the hinge pin can be dropped into place through the aligned bracket holes. A relatively tight fit between the holes and the pin is required to prevent a sloppiness in the subsequent opening and closing movements of the door.
Specifically, the pin tends to bind in the upper hinge assembly pair of aligned holes, such that entry of the pin into the lower pair of aligned holes is impeded, requiring tedious and time-consuming manual alignment of the pin with the axis of the aligned bracket holes. Any build-up of paint on the pin from the prior paint spray operation further impedes the alignment and assembly of the hinge pin. The prior art hinge pin for a vehicle hinge assembly has consisted of a large upper diameter and a small lower diameter, wherein the binding occurs around the upper diameter serving to stop the downward progress of the pin toward the lower openings.
Other known prior art hinge pins include Fade U.S. Pat. No. 1,429,416, disclosing a non-rotatable bolt having a square or otherwise formed center segment to cooperate with both a similarly formed aperture in a hinge collar slidably mounted on the lower end of the pin and an opening through an upper hinge lug to prevent rotation of the bolt therein.
Tolle U.S. Pat. No. 4,979,263 discloses a hinge pin having a screw head three successive axially extending portions with decreasing diameters. The middle axial portion is provided with a self-cutting thread for being rigidly but releasably connected to a door-holding rod.
Valenti U.S. Pat. No. 4,573,239 discloses a two-diameter hinge pin. Other known hinge assemblies include single diameter pins.